1. Field of the Invention
The present invention relates to a method for controlling the pressure dynamics and estimating the life cycle of the combustion chamber of a gas turbine.
2. Description of the Related Art
The use of gas turbines, normally consisting of a multiphase compressor, in which the air sucked from the outside is compressed, a combustion chamber, in which the combustion takes place of gaseous fuel added to the compressed air, and a turbine or expander, in which the gases coming from the combustion chamber are expanded, is known for the production of electric energy. The turbine is then capable of generating mechanical energy which can be exploited for activating operating machines or for feeding electric generators.
Current methods for controlling the pressure dynamics of the combustion chamber of a gas turbine envisage that a certain protection action only be exerted after stress, having a specific level of amplitude, has been verified for a certain period of time. Furthermore, only a limited number of critical amplitudes is taken into consideration, whereas the periods of time are established on the basis of estimations based on experience.
The result obtained is that the action aimed at protecting the integrity of the combustion chamber and consequently of the turbine, is only exerted beyond a certain fatigue threshold, whereas the fatigue life cycle of the components of the turbine itself can also terminate below this threshold. As is known, fatigue is a mechanical phenomenon whereby a material subjected to varying loads with time, either regularly or casually, is damaged to breakage, even if the maximum intensity of the loads in question is much lower than that of breakage or static yield of the material itself.
An objective of the present invention is therefore to provide a method for controlling the pressure dynamics and for estimating the life cycle of the combustion chamber of a gas turbine, capable of establishing, on the basis of measurements of the pressure oscillations and using particular control and evaluation instruments, the admissible fatigue threshold for the same combustion chamber, allowing the due protection actions to be undertaken when excessive increases in pressure arise.
A further objective of the invention is to provide a method for controlling the pressure dynamics and for estimating the life cycle of the combustion chamber of a gas turbine, in which it is possible, on the basis of the data obtained, to optimize the maintenance intervals on the components of the combustion chamber itself.